Mastro's is a very good steak and seafood restaurant in the Crystal's shopping mall next to Aria on the second floor.
It's best to make reservations ahead of time or you wait.
Service was prompt and courteous. I enjoyed a delicate Malbec (it doesn't give me migraine headaches like other wines do). My husband and I split a Wedge salad that was perfectly mixed with blue cheese, cheddar cheese, bacon and onions. My husband really enjoyed the bone-in ribeye and I couldn't finish the delicious Artic Char I was served. The double baked potato was gargantuan and awesomely scrumptious, but the best part was ordering creme brulee' and to be served a giant wallop of real whipped cream bigger than the dessert portion! Simply delightful.